The present invention relates to the field of control systems, and more particularly, to a control system for a vehicle.
Vehicle security systems are widely used to deter vehicle theft, prevent theft of valuables from a vehicle, deter vandalism, and to protect vehicle owners and occupants. A typical automobile security system, for example, includes a central processor or controller connected to a plurality of vehicle sensors. The sensors, for example, may detect opening of the trunk, hood, doors, windows, and also movement of the vehicle or within the vehicle. Ultrasonic and microwave motion detectors, vibration sensors, sound discriminators, differential pressure sensors, and switches may be used as sensors. In addition, radar sensors may be used to monitor the area proximate the vehicle.
The controller typically operates to give an alarm indication in the event of triggering of a vehicle sensor. The alarm indication may typically be a flashing of the lights and/or the sounding of the vehicle horn or a siren. In addition, the vehicle fuel supply and/or ignition power may be selectively disabled based upon an alarm condition.
A typical security system also includes a receiver associated with the controller that cooperates with one or more remote transmitters typically carried by the user as disclosed, for example, in U.S. Pat. No. 4,383,242 to Sassover et al. The remote transmitter may be used to arm and disarm the vehicle security system or provide other remote control features from a predetermined range away from the vehicle.
Other vehicle security systems may be associated with the ignition of the vehicle. More particularly, one type of conventional vehicle security system includes a passive transponder either carried by the keychain or embedded in the ignition key. When the transponder is positioned adjacent the ignition switch, the transponder is inductively powered and transmits a uniquely coded signal to a receiver in the vehicle. When a properly coded transponder is detected, the vehicle engine may be allowed to start, for example. In other words, an ignition or fuel cutoff is normally operative to prevent the engine from starting or running, unless the proper transponder is sensed. Accordingly, vehicle security is increased.
The security system may have multiple transponders capable of disabling the ignition or fuel cutoff to thereby permit operation of the vehicle. These uniquely coded transponders may be added or deleted from the vehicle controller. Unfortunately, the owner of the vehicle may not know that a transponder has been added without authorization.
U.S. Pat. No. 5,513,105 to Krones, for example, discloses a vehicle security system including a so-called xe2x80x9ccomputerized keyxe2x80x9d which sends a unique digitally encoded signal through a so-called xe2x80x9ckeyportxe2x80x9d in the vehicle to a processor and controller in the vehicle. The vehicle starting is interrupted unless the proper computerized key is presented to the keyport. A valet mode is also possible wherein the computerized key is not needed. In addition, the system may be reprogrammed to accept new replacement keys. The processor and controller may be programmed to accept and recognize authorization of a plurality of computerized keys, each having individual uniquely identifying digital numbers stored therein. A program mode may be entered by presenting an authorized key for set time, then presenting new keys to be added. In the event that the memory has been filled, a long beep is indicated and the program mode is terminated. A lost key function permits a user to return the system to the program mode and thereby authorize a new set of keys to the exclusion of the previously authorized keys. Entering the lost key mode involves disconnecting the vehicle battery for a set time.
U.S. Pat. No. 5,055,701 to Takeuchi discloses a keyless entry system using a random code portion to prevent code stealing. Along these lines, U.S. Pat. No. 4,928,098 to Dannhaeuser also discloses an electronic key wherein a new coinciding code is automatically set in the infrared transmitter and receiver after each transmission and reception event. U.S. Pat. No. 5,563,579 to Carter discloses a security system for a plurality of cars, such as on a car dealer parking lot. A key storage box is mounted to the vehicle window. The storage box also includes a sensor for determining whose key is being used to unlock the box.
Unfortunately, conventional vehicle security systems using transponders have tended to attempt to increase transponder security by adding random or pseudorandom coding to the passive transponders. Unfortunately, a security threat still exists based upon unauthorized learning of a uniquely coded transponder or other token, for example. Once such a transponder or token has been learned, the would-be thief can return to the vehicle and defeat the security system.
In view of the foregoing background, it is therefore an object of the invention to provide a vehicle control system and related method for reducing the risk of an unauthorized token being able to operate the vehicle control system.
It is another object of the present invention to provide a system and method for reducing the risk of an unauthorized token being able to operate the vehicle control system, and also permitting the owner to readily return the system to the correct operating condition after an unauthorized token has been more recently learned.
These and other objects, features, and advantages in accordance with the present invention are provided by a vehicle function control system including a token reader at the vehicle, and a controller at the vehicle for controlling at least one vehicle function responsive to the token reader. The controller preferably includes token learning means for learning the unique code of the token to define a learned token capable of controlling the vehicle function, and token verifying means for generating an indication relating to whether a new token has been learned by the token learning means to thereby alert the user of a potentially unauthorized token capable of controlling the vehicle function.
The uniquely coded token may include at least one first electrical conductor, and the token reader may include at least one second electrical conductor for connecting to the at least one first electrical conductor of the uniquely coded token and for reading the unique code. The uniquely coded token may include a uniquely coded integrated circuit, or a coded resistor matrix, for example. Also, the vehicle function control system may include a key, and the uniquely coded token may be positioned in the vehicle ignition key.
Another aspect of the invention is that the controller may comprise engine enabling means for enabling operation of the vehicle engine responsive to connecting of the learned token to the reader. In addition, the controller may include door unlocking means for unlocking of a vehicle door responsive to connecting the token to the token reader.
The token learning means may be switchable between a learning mode permitting learning of at least one token, and a secure mode. In one embodiment, the token learning means may include token deleting means for deleting all prior learned tokens based upon entering the learning mode.
The token verifying means may further include learning mode entered indicating means for indicating that the learning mode of the token learning means has been entered. The learning mode entered indicating means may comprise time lapse means for indicating when the learning mode of the token learning means has last been entered. The time lapse means, in turn, may comprise means for progressively indicating a passage of time since the learning mode has last been entered.
Alternately, the token verifying means may include learned token number indicating means for indicating a number of learned tokens. The token verifying means may also alternately include learned token change indicating means for indicating a change in a number of learned tokens or means for generating an indication relating to whether a new token has been learned by the token learning means. The verifying means may further comprise activating means for causing the indicating means to generate an indication.
Another aspect of the invention relates to the ease of returning the system to operate from a previous authorized set of tokens. According to this aspect, the vehicle function control system preferably further includes token code reset means for permitting the user to restore at least one previously learned code and remove at least one more recently learned code. The token verifying means may enter a warning mode and remains in the warning mode for a predetermined warning time responsive to a new uniquely coded token being learned. In addition, learned codes designated as current are capable of controlling at least one vehicle function, and codes designated hold are capable of being changed to current. Thus, the token code reset means may include means for changing at least one code from current to hold responsive to learning a new uniquely coded token.
The token code reset means preferably further comprises means for learning at least one new uniquely coded token as a temporary code which is also capable of controlling at least one vehicle function. The token code reset means may also include means for deleting hold codes, and converting temporary codes to current codes responsive to expiration of the predetermined warning time. In addition, the token code reset means may delete temporary codes and maintain hold codes responsive to learning a new uniquely coded token when in the warning mode.
The token code reset means may include restore means for restoring hold codes to current codes, and for deleting temporary codes responsive to learning a new uniquely coded remote token matching a hold code and when in the warning mode. Also, the restore means may cause exit from the warning mode.
A method aspect of the invention is for controlling at least one vehicle function using at least one uniquely coded token for being carried by a user. The method preferably comprises the steps of: reading the token at the vehicle via the at least one electrical conductor of the token; providing a controller at the vehicle for controlling at least one vehicle function responsive to reading the token; learning the unique code of the at least one token into the controller to define a learned token capable of controlling the at least one vehicle function; and generating an indication relating to whether a new token has been learned into the controller to thereby alert the user of a potentially unauthorized token capable of controlling the at least one vehicle function. The method may also include the step of restoring at least one previously learned code and removing at least one more recently learned code.